CVE-2026-46392

HAX CMS helps manage microsite universe with PHP or NodeJs backends. Prior to version 26.0.0 of HAX CMS PHP, the `saveFile` endpoint validates upload extensions case-insensitively and writes the filename to disk verbatim, but the `.htaccess` rule that forces `Content-Disposition: attachment` on HTML files is case-sensitive. An HTML file uploaded with an uppercase extension (`.HTML`, `.Html`, `.HTM`) is still served as `text/html` but the forced-download header never applies, so the browser renders it inline and executes any embedded JavaScript in the HAXcms origin. This bypasses the mitigation shipped for CVE-2026-22704. Version 26.0.0 contains a fix.

CVSS 3.1

8.7CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N

EPSS

0.2% chance of exploitation in the next 30 days; higher than 12% of CVEs (scores of 2026-10-25)

CWEs

CWE-178, CWE-434

Published

2026-06-05

Modified

2026-10-26

Record from

the NVD, synced 2026-10-26

References

• https://github.com/haxtheweb/issues/security/advisories/GHSA-hg33-w4j2-95qp
• https://github.com/haxtheweb/issues/security/advisories/GHSA-hg33-w4j2-95qp

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